Hello, I would suggest to eventually launch a hull painting "fan texture-art" (not sure how you would call it) contest. Those few or many winners would have their textures in the painting tool, into a new tab called "fan" (you bet? I am sure there a many talented players who will create gems :-() Not sure how you would manage this. Eventually players to send you the texture file. and make some "experimental" version for players to hop-in and try the textures. Then an outer survey cms to gather the votes...
You want to include links to how to use Unity editor free and optionally Blender with some pointers as to how to do so. Then you will get a few takers.